basic + fundamental: Clean up includes

Split out of #37344.

src/basic/forward.h

@@ -85,6 +85,7 @@ typedef enum CGroupFlags CGroupFlags;
 typedef enum CGroupMask CGroupMask;
 typedef enum ChaseFlags ChaseFlags;
 typedef enum ExtractFlags ExtractFlags;
+typedef enum Glyph Glyph;
 typedef enum ImageClass ImageClass;
 typedef enum JobMode JobMode;
 typedef enum RuntimeScope RuntimeScope;